Superconductivity induced by oxygen deficiency in Sr-doped LaOFeAs

Abstract

We synthesized Sr-doped $L{a}_{0.85}S{r}_{0.15}OFeAs$ sample with single phase, and systematically studied the effect of oxygen deficiency in the Sr-doped LaOFeAs system. It is found that substitution of Sr for La indeed induces the hole carrier evidenced by positive thermoelectric power (TEP), but no bulk superconductivity is observed. The superconductivity can be realized by annealing the as-grown sample in vacuum to produce the oxygen deficiency. With increasing the oxygen deficiency, the superconducting transition temperature ($T_c$) increases and maximum $T_c$ reaches about 26 K the same as that in La(O,F)FeAs. TEP dramatically changes from positive to negative in the nonsuperconducting as-grown sample to the superconducting samples with oxygen deficiency. While $R_H$ is always negative for all samples (even for Sr-doped as grown sample). It suggests that the $L{a}_{0.85}S{r}_{0.15}{O}_{1-\delta }FeAs$ is still electron-type superconductor.

4 pages, 4 figures

References in corpus (9)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO${}_{1-x}$F${}_x$FeAs
• Superconductivity and Phase Diagram in the Iron-based Arsenic-oxides ReFeAsO1-delta (Re = rare earth metal) without F-Doping
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Thorium-doping induced superconductivity up to 56 K in Gd1-xThxFeAsO
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• Nernst effect of the new iron-based superconductor LaO${}_{1-x}$F${}_x$FeAs

Cited by in corpus (14)

• Superconductivity in Iron Compounds
• Effect of Co doping on superconductivity and transport properties in SmFe${}_{1-x}$Co${}_x$AsO
• Superconductivity induced by cobalt doping in iron-based oxyarsenides
• Synthesis, crystal structure and chemical stability of the superconductor FeSe_{1-x}
• The Unusual Superconducting State at 49 K in Electron-Doped CaFe2As2 at Ambient
• Synthesis and properties of SmO0.5F0.5BiS2 and enhancement in Tc in La1-ySmyO0.5F0.5BiS2
• Structural and electronic response upon hole-doping of rare-earth iron oxyarsenides Nd1-xSrxFeAsO (0 < x < 0.2)
• Electronic and lattice dynamical properties of the iron-based superconductors LiFeAs and NaFeAs
• High Pressure Synthesis of Indirectly electron-doped 122 Iron Superconductor Sr1-xLaxFe2As2 with a maximum Tc = 22 K
• Doping Dependence of Superconductivity and Lattice Constants in Hole Doped $L{a}_{1-x}S{r}_{x}FeAsO$
• Theoretical investigation of magnetic order in ReOFeAs, Re = Ce, Pr
• Structural study on hole-doped superconductors Pr1-xSrxFeAsO
• Superconductivity in layered iron Selenide induced by cobalt- and sodium-doping
• Nematicity in LaFeAsO single crystals studied by elastoresistance, high-resolution thermal expansion and shear-modulus measurements